The irreducible complexity argument is based on the claim that evolution cannot produce a certain system. As soon as a feasible evolutionary route is proposed that argument falls apart.
What can generally be observed empirically is typically a form of irreducible complexity where if a part is taken away then a lack of function results. For sociological, psychological, political, theological or some other reason many scientists do not treat what is generally observed as the evidence that it is. Look at yourself for example, you neglect empirical observation and instead focus on proposing "feasible evolutionary" routes in line with Darwinian reasoning: "If an organism could be found which I could not imagine coming about in a gradual sequence of events then my theory would absolutely break down." For some reason those who are the first to blindly assert: "There is no evidence." also seem to be those most willing to cite their own imaginations as the equivalent of empirical evidence.
Irreducible complexity isn't an "argument" similar to Darwinian reasoning, it's generally an empirical observation which can be observed in the form and function of organisms. If one does not go the Darwinian route of imagining your own imagination to be the equivalent of empirical evidence you quickly see that the capacity to imagine things doesn't change empirical facts or explain the history of all biological specification, form and species. (Link)